How do beginners develop a high-quality J2EE system

J2EE is becoming more and more learners, J2EE technology is constantly evolving, and various concepts are emerging. This article attempts to explain these concepts from an easy-to-understand perspective to beginners, so as to grasp the learning direction of J2EE.
First of all, we need to know that Java and J2EE are two different concepts. Java is not just a language, but has already represented another huge camp different from Microsoft, therefore, Java sometimes refers to a genre of software systems. NET and Java.
J2EE can be said to be implemented by Java on the database information system, from the early dBase to C/S structures such as Delphi/VB, developed to the B/S (Browser/Server) structure, while J2EE mainly refers to the implementation of the B/S structure.
J2EE is a framework and standard. The framework is similar to the concepts of APIs and libraries, but beyond them. If you need a detailed understanding of the framework, you can first learn from the design mode.
J2EE is a big concept of virtual reality. The J2EE standard mainly includes three sub-technical standards: WEB technology, EJB technology and JMS. When talking about J2EE, we should say that the three sub-concepts should be implemented in the end.
Each of these three technologies involves two parts in application: container and application, and Web container is also a Jsp/Servlet container. If you want to develop a Web application, jsp/Servlet library or API support (except JDK/J2SE) is required for both compiling and running ).
In addition to the Jsp/Servlet technology, the Web technology also requires JavaBeans or Java Class to implement some functions or package and carry data. Therefore, the Web technology was initially referred to as the Jsp/Servlet + JavaBeans system.
Speaking of the JavaBeans technology, it involves the component technology (component), which is the core foundation of Java. Many software design concepts (design patterns) are implemented through JavaBeans.
JavaBeans are not in the scope of J2EE concepts. If a JavaBeans object is called by Web technology (that is, Jsp/Servlet), the JavaBeans will run in the J2EE Web container; if it is called by EJB, it runs in the EJB container.
EJB (Enterprise JavaBeans) is an improvement and specification of common JavaBeans, because enterprise information system development requires a scalable performance, transaction, and security mechanism, which can ensure the smooth development of enterprise systems, instead of changing a software system at a scale.
So far, after the development of the JavaBeans component to EJB, it does not mean that the previous JavaBeans form disappears, which naturally forms two kinds of JavaBeans technology: EJB and POJO, POJO is completely different from the EJB concept. It refers to the common JavaBeans, and the JavaBeans are not attached to a framework. Or you can simply say that this JavaBeans is created for the application separately.
There are many J2EE application system development tools, such as JBuilder and Eclipse. These IDEs are first Java development tools. That is to say, their primary basic function is to develop JavaBeans or Java classes, however, to develop a J2EE system, you must implement either Web or EJB technology. Therefore, you may need some special module functions (for example, eclipse requires the lomboz plug-in ), most importantly, because the J2EE system is divided into two parts: container and application, you must specify the J2EE container for developing J2EE in any development tool.